Add hashtag trendline support to glitch-soc flavour
Port Mastodon's hashtag stats thing to glitch-soc.
This doesn't change how hashtags are ordered, and doesn't add a trending
hashtags section, but it does change how hashtag searches are rendered,
displaying a trend line alongside each hashtag.
<FormattedMessageid='trends.count_by_accounts'defaultMessage='{count} {rawCount, plural, one {person} other {people}} talking'values={{rawCount:hashtag.getIn(['history',0,'accounts']),count:<strong>{shortNumberFormat(hashtag.getIn(['history',0,'accounts']))}</strong> }} />